1/* 2 * This program is free software; you can redistribute it and/or modify it 3 * under the terms of the GNU General Public License version 2 as published by 4 * the Free Software Foundation. 5 * 6 */ 7#include <linux/rtc.h> 8#include <linux/time.h> 9 10/** 11 * rtc_set_ntp_time - Save NTP synchronized time to the RTC 12 * @now: Current time of day 13 * 14 * Replacement for the NTP platform function update_persistent_clock 15 * that stores time for later retrieval by rtc_hctosys. 16 * 17 * Returns 0 on successful RTC update, -ENODEV if a RTC update is not 18 * possible at all, and various other -errno for specific temporary failure 19 * cases. 20 * 21 * If temporary failure is indicated the caller should try again 'soon' 22 */ 23int rtc_set_ntp_time(struct timespec64 now) 24{ 25 struct rtc_device *rtc; 26 struct rtc_time tm; 27 int err = -ENODEV; 28 29 if (now.tv_nsec < (NSEC_PER_SEC >> 1)) 30 rtc_time64_to_tm(now.tv_sec, &tm); 31 else 32 rtc_time64_to_tm(now.tv_sec + 1, &tm); 33 34 rtc = rtc_class_open(CONFIG_RTC_HCTOSYS_DEVICE); 35 if (rtc) { 36 /* rtc_hctosys exclusively uses UTC, so we call set_time here, 37 * not set_mmss. */ 38 if (rtc->ops && (rtc->ops->set_time || rtc->ops->set_mmss)) 39 err = rtc_set_time(rtc, &tm); 40 rtc_class_close(rtc); 41 } 42 43 return err; 44} 45